Boron nitride (BN)-substituted nanographene molecules
are currently
the focus of interest because the substitution of C–C units
by isoelectronic and isosteric BN units is a straightforward way for
tuning of their electronic properties. We investigated interface properties
of BN-doped B3N3-hexa-peri-hexabenzocoronene
(BN-HBC) and B3N3-hexabenzotriphenylene (BN-HBP)
on metals with different reactivities using photoelectron spectroscopy
(PES). As a reference, HBC was studied on Au(111), Cu(111), and Ni(111)
by PES and scanning tunneling microscopy. The substitution of the
inner benzene ring of HBC by a borazine core changes the nature of
the interaction in the case of more reactive Cu(111) and Ni(111) substrates.
Whereas for the planar BN-HBC, chemical interaction occurs mainly
via outer C atoms, the inner BN ring is affected in the case of the
nonplanar BN-HBP. The stability of the inner ring is expected to be
a prerequisite for a successful preparation of well-defined, large-area,
BN-doped graphene layers from bottom-up synthesis.